<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>important</title>
</head>
<body>
<h1 style="background-color: yellow">
    很雕哦
</h1>
<h2 style="background-color:gray ">
    沙雕
</h2>
<h3>
    大嵟
</h3>
<style>
    h1{
        background-color: red;
    }
    h1{
        background-color: #1abc9c !important;
    }
     h2 {
        background-color: #b490ca  ;
    }

</style>
</body>
</html>